This is what I got...
It seems to decompile, but the same files are still there... I think...
rex:~ esmith$ cd /Users/esmith/Documents/ACPI_Files
rex:ACPI_Files esmith$ iasl -da -dl DSDT.aml SSDT*.aml
Intel ACPI Component Architecture
ASL+ Optimizing Compiler version 20161210-64(RM)
Copyright (c) 2000 - 2016 Intel Corporation
Input file DSDT.aml, Length 0xA562 (42338) bytes
ACPI: DSDT 0x0000000000000000 00A562 (v02 DELL CBX3 00000021 INTL 20091112)
External object resolution file SSDT-7-NvdTabl.aml
Input file SSDT-7-NvdTabl.aml, Length 0x198A (6538) bytes
ACPI: SSDT 0x0000000000000000 00198A (v01 NvdRef NvdTabl 00001000 INTL 20091112)
Pass 1 parse of [SSDT]
Pass 2 parse of [SSDT]
External object resolution file SSDT-6x-ApCst.aml
Input file SSDT-6x-ApCst.aml, Length 0x119 (281) bytes
ACPI: SSDT 0x0000000000000000 000119 (v01 PmRef ApCst 00003000 INTL 20051117)
Pass 1 parse of [SSDT]
Pass 2 parse of [SSDT]
External object resolution file SSDT-5x-Cpu0Cst.aml
Input file SSDT-5x-Cpu0Cst.aml, Length 0x523 (1315) bytes
ACPI: SSDT 0x0000000000000000 000523 (v01 PmRef Cpu0Cst 00003001 INTL 20051117)
Pass 1 parse of [SSDT]
Pass 2 parse of [SSDT]
External object resolution file SSDT-4x-ApIst.aml
Input file SSDT-4x-ApIst.aml, Length 0x303 (771) bytes
ACPI: SSDT 0x0000000000000000 000303 (v01 PmRef ApIst 00003000 INTL 20051117)
Pass 1 parse of [SSDT]
Pass 2 parse of [SSDT]
External object resolution file SSDT-3x-CpuPm.aml
Input file SSDT-3x-CpuPm.aml, Length 0xB22 (2850) bytes
ACPI: SSDT 0x0000000000000000 000B22 (v01 PmRef CpuPm 00003000 INTL 20051117)
Pass 1 parse of [SSDT]
Pass 2 parse of [SSDT]
External object resolution file SSDT-2-CpuPm.aml
Input file SSDT-2-CpuPm.aml, Length 0xB22 (2850) bytes
ACPI: SSDT 0x0000000000000000 000B22 (v01 PmRef CpuPm 00003000 INTL 20051117)
Pass 1 parse of [SSDT]
ACPI Error: [SSDT] Namespace lookup failure, AE_ALREADY_EXISTS (20161210/dswload-462)
ACPI Exception: AE_ALREADY_EXISTS, During name lookup/catalog (20161210/psobject-310)
Could not parse external ACPI tables, AE_ALREADY_EXISTS
rex:ACPI_Files esmith$